The present invention relates to a linear slide bearing suitable for use in various sliding parts such as the table saddle of a machine tool, the slider of a machining center, and the slider of a transportation robot for reciprocative transportation of a heavy object.
In a typical conventional linear slide bearing, a pair of left and right bearing races 112, 113 are individually fixed as shown in FIG. 21, for example. In consequence, the number of processes required for mounting the bearing races is increased as compared with a bearing of the type in which a pair of left and right bearing races are simultaneously fixed, to make the mounting operation troublesome. In addition, since it is difficult to effect adjustment so that both the bearing races 112, 113 are fixed in a balanced state, the contact pressures between balls and the bearing races are apt to be nonuniform, which constitutes a main cause to prevent a smooth recirculation of the balls, disadvantageously. Further, in the prior art, the pair of left and right bearing races 112, 113 are fixed to a main body 110 of the linear slide bearing by means of screws. Therefore, when the bearing races must be fixed to the main body at many points, it is troublesome to conduct the fixing operation, inconveniently. Moreover, when the bearing races are fixed by means of screws, it is difficult to adjust the screw tightening force; hence, it is impossible to properly locate and mount the bearing races 112, 113 so as to correctly position, particularly, the curvature centers of ball rolling surfaces 114, 115 formed on the bearing races 112, 113, respectively, or obtain the verticalness of the bearing races 112, 113. In consequence, the contact pressures of the balls, which are interposed between the ball rolling surfaces 114, 115 on the bearing races 112, 113 and ball rolling surfaces 119, 120 formed on a track shaft 116, become nonuniform to make it impossible to effect a smooth recirculation of the balls, as well as cause the ball rolling surfaces 114, 115, 119, 120 to be unevenly worn, unfavorably. Furthermore, in the conventional linear slide bearing, each of the bearing races 112, 113 is made of a flat plate member and therefore easily twisted when a load is applied thereto. As a result, it becomes impossible to maintain parallelism between the ball rolling surfaces 114, 115 on the bearing races 112, 113 and the ball rolling surfaces 119, 120 on the track shaft 116, so that the contact pressures of the balls become nonuniform, disadvantageously.